<script setup>

    let activeClass = "active"
    let lineClass  = "line"

    let myClass = ["active", "line"]

</script>

<template>
<div class="active line">Hello, World!</div>
<!-- 数组的原始最终是字符串元素，每个元素对应一个外部样式类 -->
<div v-bind:class="['active', 'line']">Hello, World!</div>
<div v-bind:class="[activeClass, lineClass]">Hello, World!</div>
<div v-bind:class="myClass">Hello, World!</div>
</template>

<style scoped>
    .active {
        color: red;
    }

    .line {
        text-decoration: underline
    }
</style>